Firstly like so many before me I am starting with an apology. Sorry if this question has been asked before but I have tried to find the answer and cannot, even though I'm sure it is out there and probably right under my nose!

I am 48 from the UK and entered Thailand on a multiple enrty visa based on marriage in July this year. My departure stamp in my passport is 29 Sept. I have not applied for an extension and was just planning on returning to the UK for a week around the 27 Sept, hoping to then get another 3 month stamp on my return to Thailand in early Oct.

All seemed straight forward but I now have to go to the UK within the next week, I do not want to stay for long so will be coing back to Thailand before my original departure stamp date of 29 Sept.

Simple question is will I get another 3 month stamp from my return date or will they just stick to the original date and then expect me to leave again by the 29 Sept ?

Apologies if this seems dumb but all my previous visits have been short term and I have never had to consider visa issues until now.

Any help greatly appreciated.

You are free to enter/exit at will during the period your multi entry non immigrant O visa is valid (that is the date on visa itself). Each entry will receive a 90 day permitted to stay stamp. That stamp ends on any departure and a new one is received when you return. No problem. And you do not want to buy a re-entry permit - that is for those without multi entry visas and on extensions of stay.

Thanks lopburi, you even answered a question that I had thought about but not posted i.e. the re-entry permit.

I got a 60-day entry on my non-B multiple entry the first time I came in last year. I came in October 3 and got a stamp until December 1. I just looked at my passport and noticed it and was befuddled. A mistake by immigration? Seems it IS up to them but everyone always seems like they get 90 days, yes?

They probably picked up the wrong stamp (tourist visa) so you got 60 instead of the normal 90 day entry. That is why you should always check immediately as it does happen and can easily be corrected if you notice.

Oh I see, you said they picked up the wrong stamp, not looked at the wrong visa.